Automatic gun control for tanks



M 15, 1947. A, R, ONE 2,423,856

XUTOMATIC GUN CONTROL FOR TANKS 7 Filed June 24, 1943 IIE nu awe/whom EAlba-r1; R- Einne Patented July 15, 1947 UNITED STATES PATENT OFFICE2,423,856 AUTOMATIC GUN CONTROL FOR TANKS Albert Rivington Stone,Belair, Md.

Application June 24, 1943, Serial No. 492,139

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370O. G. 757) 13 Claims;

The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment to me ofany royalty thereon.

This invention relates to the positioning or training of guns carried bytanks and other vehicles, and more particularly to means for rotatingthe gun in response to the changes in directions of the tank.

Assume, for an example, a, tank moving along a rectilinear east to westcourse with its gun trained on a target positioned directly north. Asthe tank progresses on its east to west course, the gunner keeping thetarget in sight will rotate the gun turret in a clockwise direction.This manual traversing rotation of the gun is required solely by therectilinear travel of the tank, i. e., it is not occasioned by change indirection, since the tank course is assumed to be rectilinear. Supposenow that the tank changes its direction by veering to a west-south pointof the compass, making a 45 angle to the original east-west path of thetank, i. e., in a counterclockwise sense. This change in direction ofthe tank requires a very considerable rotation of the gun turret in aclockwise sense. The purpose of this invention is to provide mechanicalmeans which will automatically rotate the gun turret in this manner, tocompensate for the change in direction of tank movement. Of course thisautomatic gun rotation will not maintain the gun trained on the target;the gunner will be required, to additionall rotate the gun turret tokeep the target in sight, the extent of such additional gun rotationwill depend on the speed of the tank and other factors. The gun rotationimparted by the device of this invention will merely maintain the gunaimed in the general direction of the target. To explain, if the gun hadbeen pointed north in the example above assumed, the device of thisinvention will maintain the gun pointing to the north. But thesouth-north line through. the gun will hav been moved or offset to thewest, due to the movement of the tank in that general direction.

An embodiment of the automatic positioning or compensating device ofthis invention is shown in the accompanying drawings, wherein:

Fig. 1 is a plan view of the center and rear portion of a tank, showingthe rear drive transmission and the gun turret, together with thecompensating mechanism of this invention.

Fig. 2 is a plan view of a power-providing mechanism to supplement theSelsyn system employed between the tank drive and the gun turret.

Fig. 3 is a side elevation of the mechanism of Fig. 2.

Fig. 4 is a section on the line 44 of Fig; 3.

Fig. 5 is a detail of the solenoid drive employed in the mechanism ofFigs. 2 to 4.

The center and rear portion of a tank designated l is shown in Fig. 1,with left and right wheels or track sprockets, respectively, 2 and 3.The two wheels are connected by flexible shaft cable 4 or the like to adifferential, which will be designated as the primary differential todistinguish from other difierentials subsequently described. The leftwheel 2 is operatively connected to one of the bevel gears I2ofdifferential i0 while the right wheel is operatively connected to theother bevel gear l3. It should be noted that the bevel gear ib at thewheel end of the flexible shaft connection to the left wheel meshes withthe left Wheel bevel'2a 0n the side thereof opposite to the side atwhich the bevel gear 51) at the wheel end of the right wheel meshes withthe bevel 3a. Hence the two bevels of primary differential ID will berotated by their respective tank wheels in opposite directions. If thetank is traveling along a rectilinear path, the two bevels will beturning at the same rate but in opposite directions. Hence the output orspider member ll of the primary difierential will remain stationary, itsplanetary bevels turning idly.

The output shaft of the primary differential is connected to thetransmitter l5 of a Selsyn transmission, the receiver, pick-ofi andfollowu unit 25 of which is positioned close to the gun turretrepresented in Fig. 1 by the large crown gear 6. The Selsyn receiver 25is connected, through a power-providing means subsequently described, toone of the bevels 21 of a difierential which will be referred to as thebalancing differential for reasons soon apparent. The other bevel ll ofthe balancing difierential is connected by a shaft 1 and the gears shownto the said crown gear 6 of the gun turret. The output or spider member28 of the balancing differential is connected to one bevel 3B of a thirddifferential, the other bevel 39 of which is turned by a handwheel 9.The output or spider member of the third differential is connected to anoilgear valve 18 which forms part of a hydraulic system which includes ahydraulic motor 8 geared to the crown gear '5 of the gun turret.

When the tank is caused to change its direction, the wheels 2 and 3 willturn at different speeds, thus causing a turning of the output member Hof the differential which depends upon the diilerence in wheel speedsand hence the extent of turning or change of direction of the vehicle.To reduce false effect upon the primary differential due to rapidslipping of one or both of the wheels or tracks, acceleration limitcoupling 5 are inserted in the flexible shaft connection from the tankwheels to the primary differential; friction clutches in theacceleration limit couplings are caused to slip when the wheel shaftstend to accelerate above a predetermined limit. The precise degree ofturning of the output shaft of the primary differential is transmittedby the Selsyn system l525 through the balancing differential to thecombining differential which causes the oilgear valve l8 to open thuscausing hydraulic pressure, from an accumulator (not shown), to motivatemotor 8 and rotate the gun turret in accordance with the extent of tankchange of direction. As explained above, the gunner meanwhile wouldmanually turn the gun turret as he endeavors to keep the target insight; this he does by means of handwheel 9. It is thus seen that theoutput from the balancing differential and the manual turning ofhandwheel 9 are combined at this differential; the combined output ofmanual gun training and the automatic gun turning takin into accountvehicle change of direction are thus transmitted to the oilgear valve|8.

The oilgear valve l8 would remain in open position, to the extent it hasbeen opened by manual gear training and automatic gear turning-and thuscontinue to motivate motor 8, were it not for the presence of thebalancing differential. The turning of the gun turret, combined manualand automatic operation, as described, causes, through its crown gear 6and the shaft 1, rotation of bevel gear I! of the balancing differentialin a direction opposite to the rotation of bevel 21 and to an extentequal to the combined turning of the gun turret. This rotation of bevelll of the balancing differential is transmitted through the combiningdifferential to the oilgear valve l8, thus moving it to closed position.

The Selsyn system, more particularly, its receiver or motor 25', isincapable of driving the heavy mechanism of the differentials and theirconnecting gears and the oilgear valve I8. The means now to be describedare provided to furnish the necessary power to accomplish such drivingunder regulatory control of Selsyn motor 25'. Aligned with the shaft 24of the Selsyn motor 25, Figs. 2 and 3, is a shaft 34 mounted in bearingsas shown. One end of shaft 34 faces Selsyn motor shaft 24. At the otherend of shaft 34 is secured the bevel 21 of the balancing differential.At the end of Selsyn motor shaft 24 is secured a lobed disc 26. A sleeveor bracket 31 has a bore smoothly fitting about shaft 34. This brackethas an arm 31 that is fixed by screws 46 to the standard or support 41for the inner end of shaft 34. A post 35 is fixed to or formedintegrally with, bracket 37. A contact blade 36 has one end fixed withina receiving aperture in the outer or distal end of post 35, as by meansof a set screw 48. The blade 36 is of steel or other conducting materialand possesses a resiliency that, in combination with its fixed end inpost 35, acts to maintain said blade in centralized position between thevertical portions of an inverted V-shaped bracket 32. The other end ofblade 36 carries a roller 33 of a size to be received between the lobesor serrations of disc 26, as clearly shown at Fig. 4. On the inner faceof both vertical legs of the U-shaped bracket 32 is secured anelectrical contact, the contact on the left leg, as viewed in Fig. 4, isdesignated 30, the right contact is designated 3 The left contact 30 iswired to a solenoid 48, see Fig. 5, the other terminal of which isgrounded; the right contact 3| is wired to a solenoid 4|, also groundedas shown. The blade 36 i wired to a source of current as shown. Thearmatures of the solenoids 46 and 4| are implemented with pawls,respectively 42 and 43 which cooperate with ratchet wheels secured onshaft 34, respectively, 44 and 45. It will be observed, best from Fig.5, that the pawls are disposed in a manner to turn shaft 34 in oppositedirections.

It will be understood that the number of serrations or lobes on disc 26is equal to the number of teeth on each of the ratchet wheels 44 and 45,and that the resiliency of blade 36 urges said blade to a centralizedposition in which it is out of engagement with contacts 30 and 3 J Whenth lobed disc 25 turns clockwise, as viewed in Fig. 4, the roller 33will be moved to the right to cause circuit-closing contact betweenblade 36 and contact 3| each time a lobe of disc 26 passes. Whenmovement of the disc is initiated, roller 33 is slightly raised andshifted to the right under the situation being discussed. When blade 36engages contact 3|, further lateral movement of the roller is preventedand, as soon as the highest portion of the lobe has passed the roller,the resiliency of the blade forces the roller downwardly into the troughbetween the lobe just passed and the next succeeding lobe. In thismanner the blade 36 is prevented from vibrating and is precluded fromany possibility of engagement with contact 36 for a clockwise rotationof disc 26. Of course, when disc 26 rotates counterclockwise, as viewedin Fig. 4, blade 36 i moved to make and break contact with 30 and isprevented from engagement with contact 3|. Thus, the contact 30 or 3|engaged b blade 36 depends upon the direction of rotation of disc 26,and the number of times contact is made depends upon and is directlyproportional to the degree of angular rotation of disc 26. Thisrotation, in turn, is proportional to the angular degree of change inheading of the vehicle. Solenoid 4D or solenoid 4| (depending upon thedirection of rotation of disc 26) is thus energized each time a lobe ofdisc 26 passes beneath roller 33, and each energization of a solenoidmoves a corresponding ratchet wheel one step through the action of thespring-retracted pawls 42 and 43. Since the number of lobes on disc 26and teeth on ratchet Wheels 44 and 45 are the same, gear 27 is rotatedstep-bystep in the same direction and through the same angle as disc 26.Thus, gear 21 i moved by follow-up power means to follow disc 26substantially synchronously and the component movement of the turreteffected through valve gear l8 and the motor controlled thereby, is atall times opposite to, and substantially equal to, the angular change inheading of the vehicle.

Rotation of the scalloped disc 26 in either direction results inapplying a series of interrupted electrical power impulses to thecorresponding solenoids. The number of impulses corresponds to theangular movement of the disc 23 and the number of scallops of the discwhich are successively engaged with the roller 33. As the disc rotates,a scallop carries the roller 33 into contact with the respectivecontact. After the projection between adjacent scallops passes theroller the latter is released and disengaged from the contact. Thisinterruption of the power supply to the solenoid de-energizes the latterand permits the pawl to be withdrawn from the solenoid under the actionof a. spring connected thereto. The

pawl is thus positioned to again rotate the ratchet wheel when thesolenoid is re-energized as the succeeding scallop in the disc againcarries the roller into engagement with the contact.

The resulting rotation of the ratchet wheels eifects a correspondingrotation of shaft 34 and bevel gear 27, In this manner the bevel gear2'! of the balancing differential is rotated proportionately to therotation of the Selsyn receiver or motor 25 and with sufficient power todrive the mechanism of the balancing and combining differentials and theoilgear Valve !8.'

I claim:

1. In an automatic gun positioning device for tanks of the type havingwheels at opposite sides thereof movable in response to the propulsionof the tank, the combination of a differential, flexible cable meansconnecting the wheels on opposite sides of the tank to respective onesof the input bevels of the differential, the said flexible cable meansbeing operatively connected to the tank wheels to rotate the saiddifferential bevels in opposite direction, a. Selsyn transmission unitincluding a transmitter driven from the output of the said differential,the receiver of the Selsyn being disposed at the gun turret of the tank,power means controlled b the said receiver,

-a crown gear associated with the turret turning mechanism, a seconddifferential one of the input bevels of which is driven by the saidpower means associated with the Selsyn receiver, a gear and shaftconnection from the said gun turret crown gear to the other differentialbevel, a third differential one of the input bevels of which is drivenby the output of said second differential, a, handwheel connected to theother bevel of said third differential, and a hydraulic pressure systemincluding a valve and a motor, the said hydraulic motor being geared tothe said turret crown gear to drive th same and the said hydraulic valvebeing operatively connected to the output of said third differential, tobe controlled thereby.

2. In an automatic gun positionin device for tanks of the type havingwheels at opposite sides thereof movable in response to the propulsionof the tank, the combination of a differential, flexible cable meansconnecting the wheels on opposite side of the tank to respective ones ofthe input bevels of the differential, the said flexible cable meansbeing operatively connected to the tank wheels to rotate the saiddifferential bevels in opposite directions, a Selsyn transmission unitincluding a transmitter driven from the output shaft of the saiddifferential, the receiver of the Selsyn being disposed at the gunturret of the tank, a crown gear associated with the turret turningmechanism, a second differential, means controlled by said receiver fordriving one of the input bevels of said second differential, a gear andshaft connection from the said gun turret crown gear to the other bevelof said second differential, a third differential one of the inputbevels of which is driven by the output of the second-mentioneddifferential, a handwheel connected to the other bevel of said thirddifferential, and a hydraulic pressure system including a valve and amotor, the said hydraulic motor being geared to the said turret gear todrive the same and the said hydraulic valve being operatively connectedto the output of said third-mentioned differential, to be controlledthereby.

3. In an automatic gun positioning device for tanks of the type havingwheels at opposite sides thereof movable in response to the propulsionof the tank, the combination of a differential, flexible cable meansconnecting the wheels on opposite sides of the tank to respective onesof the input bevels ofthe differential, the said flexible cable meansbeing operatively connected to the tank wheels to rotate the saiddifferential bevels in opposite directions, a Selsyn transmission unitincluding a transmitter driven from the output of the said differential,the receiver of the Selsyn being disposed at the gun turret of the tank,a gear associated with the turret turning mechanism, a seconddifferential, means controlled by the Selsyn receiver for driving one ofthe input bevels of said second differential, a gear and shaftconnection from the said gun turret gear to the other diiferentialbevel, a third differential one of the input bevels of which is drivenby the output of said second differential, a handwheel connected to theother bevel of said third differential, and a hydraulic pressure systemincluding a valve and a motor, the said hydraulic motor being geared tothe said turret gear to drive the same and the said hydraulic valvebeing operatively connected to the output of said third differential, tobe controlled thereby.

4. In an automatic gun positioning device for tanks of the type havingwheels at opposite sides thereof movable in response to the propulsionof the tank, the combination of a differential, flexible cable meansconnecting the Wheels on op posite sides of the tank to respective onesof the input bevels of the differential, the said flexible cable meansbeing operatively connected to the tank wheels to rotate the saiddifferential bevels in opposite directions, a Selsyn transmission unitincluding a transmitter driven from the output of the said differential,the receiver of the Selsyn being disposed at the gun turret of the tank,a gear associated with the turret turning mechanism, a seconddifferential, means controlled by said receiver for driving one of theinput bevels of said second differential, a connection from the said gunturret gear to the other bevel of said second differential, a thirddifferential one of the input bevels of which is driven by the output ofsaid second differential, a handwheel connected to the other bevel ofsaid third diiferential, and a hydraulic pressure system including avalve and a motor, the said hydraulic motor being geared to the saidturret gear to drive the sam and the said hydraulic valve beingoperatively connected to the output of said third differential, to becontrolled thereby.

5. In an automatic gun positioning device for tanks of the type havingwheels at opposite sides thereof movable in response to the propulsionof the tank, the combination of a differential, means connecting thewheels on opposite sides of the tank to respective ones of the inputbevel of the differential, the said means being operatively connected tothe tank wheels to rotate the said differential bevels in oppositedirections, a Selsyn transmission unit including a transmitter drivenfrom the output of the said differential, the receiver of the Selsynbeing disposed at the gun turret of the tank, a gear associated with theturret turning mechanism, a second differential, means controlled bysaid receiver for driving one of the input bevels of said seconddifferential, a connection from the said gun turret gear to the otherbevel of said second differential, a third differential one of the inputbevels of which is driven by the output of said second differential, ahandwheel connected to the other bevel of said third differential, and ahydraulic pressure system including a valve and a motor, the saidhydraulic motor being geared to the said turret gear *6. In an'automaticgun positioning device;for

tanks of the type havin wheelsat oppositesides thereof movable inresponse to the propulsion of the tank, the combination of. adifferential, means connecting the wheels on opposite sides of the tankto respective ones of the input'bevels of the differentiaL'the saidmeans being-operatively connected to the tank wheels to rotate the saiddi1Ter ential bevels in opposite directions, a Selsyn transmission unitincluding a transmitter driven fromxthe output-of the said differential,the receiverof the Selsyn being disposed at the gun turret of the tank,a gear associated with theturret turning mechanism, a seconddiiferential, means controlled by said'receiver for driving :one of theinput bevels of said second differential, a

hand wheel connected to the other differential bevel, and meansconnected to theoutput of the second said differential for driving thesaid tur- ;ret gear.

7. In an automatic gunpositionin devic for tanks of the type having:Wheels at opposite sides thereof movable in response to th propulsionof the'tank, the combination of a differential, means connecting thewheels on opposite sides of the tank to respective ones of'the inputbevels of the diiferential, the said means being operatively connectedto the tank wheels to rotate the said differential bevels in oppositedirections, a Selsyn transmission unitincluding a transmitter drivenfrom the output of the said diiferential, the receiver of the Selsynbeing disposed at the gun turret of the tank, a, second differential,means controlled by said receiver for driving one of the input; bevelsof said second differential, a handwheel connected to the otherdifierential bevel,

and means connected to the output of. the second said difierential fordriving the said turret.

'8. In an automatic gun positioning device for vehicles of the typehaving wheels at opposite sides thereof movable in response to thepropulsion of the vehicle and a gun turnable about a substantiallyvertical axis, the combination of a differential, means connecting thewheels on D- posite sides of the vehicle to respective ones of the inputbevels of the diiferentia'l, a Selsyn trans- 'mission unit including atransmitter driven from the output of said differential and a receiver,and

Wheels to the transmitter to actuate the latter in proportion to therelative angular movement between said wheels, 9. Selsyn receiveroperatively connected to said transmitter, and means "controlled by saidSelsyn receiver 'fOr :turning @the gun.

10. In a system for automaticallypositionjng1a gun carried for-angularadjustment about'arsubstantially vertical axis on and relatively to avehicle having a pair of wheels relatively'rotatable by and inproportion to a change in headingof said vehicle, a transmitter,differential means connecting said wheels and transmitter to actuate thelatter proportionally to said relative .rotation of said wheels", areceiver, connectionsactuating said receiver by and in proportion toactuation of said transmitter, 'power means connected to so adjust saidgun, and follow-up,means'controlled by said receiver forcontrolling'said power means.

11. In an automatic gun positioning system for vehicles of the typehaving propulsion 'meansat opposite sides thereof an relatively 'movablewhen said vehicle changes its heading, said -vehicle having-thereona guntrainable about asubstantially vertical axis, differential means havinga part operated by and proportionallyato relative movement between saidpropulsion means'and in a direction-corresponding to saidchange'in-heading, power means connected to sotrainsaid gun, servo-motormeans controlling said power means, and telemetric means connected tooperatesaid servo-motor means by-andinaccordance with the direction ofoperation of-said part.

12. The system as in claim '11, said servo-motor means includingreversible electric motor means, and reversing contacts controlled bysaid telemetric means to control the operation of saidmotor means by andin correspondence with the direction of operation ofsaid telemetricmeans.

13. In an automatic'gun positioning device for a vehicle havingpropulsion means at opposite sides thereof, said propulsion meansbeingrelatively movable upon a change in heading of .said vehicleproportionally to said change of :heading, said vehicle having a gunmounted thereon for training about a substantially vertica1axis,xpowermeans connectedto so train said gun, and means responsiveto saidrelativemovement of said-propulsion means to control said power means torotate said gun oppositely to the corresponding change in heading ofsaid vehicle.

ALBERT RIVING'I-ON STONE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 563,304 Ongley July '7, 1896710,311 Avril Sept '30, 1902 2,166,680 Creager July '18, :1939

1559525 Murphy et a1 Oct. 27, 1925 1,559,566 Farrell et a1 Nov. 3,19251,435,681 Akemann Nov. 14, 1922 1,304,269 Dawson et al vMay 2Q, "1919

